An apparatus that is configured to determine (measure) a surface shape of an optical element such as a lens or a mirror or the like includes for example a non-contact shape-measuring apparatus. In the step of manufacturing the optical element, the shape of the optical element is configured with reference to target shape dimensions by repetition of shape determination of the optical element by a shape measuring apparatus, and by corrective grinding. However, it may be the case that the temperature in the use environment when the optical element is used by assembly into an optical apparatus exhibits a large difference from the temperature (for example, normal temperature (room temperature) of approximately 23 degrees C.) for a general determination environment (for example, the manufacture environment of the optical element). Consequently, when the temperature of the use environment and the temperature of the determination environment differ, the shape of the optical element in the use environment deforms from the shape during determination. Therefore, determination of a surface shape of the optical element in the manufacture stage of the optical element should be preferably performed at the temperature of the environment in which the optical element is used. In this regard, it has been proposed to place the overall shape measuring apparatus at the same temperature as the temperature of the use environment to thereby determine the surface shape. However, when the shape measuring apparatus is used under a condition(s) that differs from the setting specification (the setting specification assumes determination for example at ambient temperature), a shape error occurs due to thermal deformation (thermal distortion) in the determination apparatus itself, and high-accuracy determination becomes difficult. On the other hand, Patent Literature 1 discloses a linear expansion coefficient determination apparatus configured to accommodate an object in an insulated container and thereby perform a high accuracy determination of the dimensional variable amount relative to temperature change in the object.